INSECTA : LEPIDOPTERA 



235 



Fio. 163. — The Common Vapourer Moth 

 (Orgyia antiqua). 



L, Larva ; M, male moth ; F, female moth. 



violet-grey colour with a light-coloured line down its back, 



spotted with red ; it has four tufts of yellowish hairs rising 



up from the first 



four abdominal 



segments, as well 



as clusters of 



other finer softer 



hairs. The sides 



of the body are 



yellow. 



These cater- 

 pillars are much 

 more active than 

 those of most 

 Lepidoptera. 

 They can quickly 

 make their way 

 over the ground 

 from one plant 

 or tree to another, and they can feed on many different kinds 

 of leaves. The caterpillars, therefore, which are hatched 

 from one batch of from one to two hundred eggs, quickly 

 scatter and so disperse the species, a process often left to the 

 females of other moths who fly from plant to plant laying 

 eggs in scattered spots. It is interesting to note that here, 

 where there is no need for the female to be active for this 

 purpose, she is practically wingless (see Fig. 163, F), 

 and never moves far from the cocoon from which she 

 emerges. Her mate finds her there, for he is winged and can 

 seek her. Her eggs are laid in one batch upon or near the 

 cocoon. Neither male nor female Vapourer Moth is capable 

 of feeding, for the proboscis is rudimentary. Since it is not 

 necessary for them to fly far and wide, it is not necessary 

 either for them to feed. The brown-coloured males fly with 

 a curious looping course, which used to be called " vapouring," 

 and hence their name. They are very common round London, 

 flying in the daytime. 



The Pale Tussock {Dasychira pudibunda) has both the male 

 and female forms winged. The caterpillar used to be known 

 as the " hop dog"; it is not, however, often found on hops nowa- 

 days, but is frequent on birch, hazel, oak, and other trees. 



